/*====================================================================*
 *
 *   Copyright (c) 2013 Qualcomm Atheros, Inc.
 *
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or
 *   without modification, are permitted (subject to the limitations
 *   in the disclaimer below) provided that the following conditions
 *   are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above
 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials
 *     provided with the distribution.
 *
 *   * Neither the name of Qualcomm Atheros nor the names of
 *     its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written
 *     permission.
 *
 *   NO EXPRESS OR IMPLIED LICENSES TO ANY PARTY'S PATENT RIGHTS ARE
 *   GRANTED BY THIS LICENSE. THIS SOFTWARE IS PROVIDED BY THE
 *   COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR
 *   IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 *   WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 *   PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
 *   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 *   LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 *   HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 *   OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 *   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *--------------------------------------------------------------------*/

/*====================================================================*
 *
 *   serial.c - Atheros Serial Line Command Buffer Management;
 *
 *   serial.h
 *
 *   this module contains a serial line command buffer and functions
 *   to encode and decode it in different formats and send or receive
 *   it over the serial line;
 *
 *   Contributor(s):
 *	Charles Maier
 *
 *--------------------------------------------------------------------*/

#ifndef SERIAL_SOURCE
#define SERIAL_SOURCE

/*====================================================================*
 *   system header files;
 *--------------------------------------------------------------------*/

#include <unistd.h>
#include <stdlib.h>
#include <stdint.h>
#include <memory.h>
#include <errno.h>

#if defined (WIN32)
#include <Windows.h>
#else
#include <sys/select.h>
#endif

/*====================================================================*
 *   custom header files;
 *--------------------------------------------------------------------*/

#include "../serial/serial.h"
#include "../tools/number.h"
#include "../tools/types.h"
#include "../tools/flags.h"
#include "../tools/error.h"

/*====================================================================*
 *   private variables;
 *--------------------------------------------------------------------*/

struct command command;

/*====================================================================*
 *
 *   void clearcommand ();
 *
 *   serial.h
 *
 *   erase the current command by writing 0s;
 *
 *--------------------------------------------------------------------*/

void clearcommand ()

{
	extern struct command command;
	memset (&command, 0, sizeof (command));
	return;
}


/*====================================================================*
 *
 *   void sendcommand (struct _file_ * port, flag_t flags);
 *
 *   serial.h
 *
 *   echo then send the command;
 *
 *--------------------------------------------------------------------*/

void sendcommand (struct _file_ * port, flag_t flags)

{
	extern struct command command;
	if (_anyset (flags, UART_VERBOSE))
	{
		write (STDERR_FILENO, command.buffer, command.length);
		write (STDERR_FILENO, "\n", sizeof (char));
	}
	if (write (port->file, command.buffer, command.length) != (signed)(command.length))
	{
		error (1, errno, "Can't write to %s", port->name);
	}
	clearcommand ();
	return;
}


/*====================================================================*
 *
 *   void readcommand (struct _file_ * port, flag_t flags);
 *
 *   serial.h
 *
 *   read response serial line and log the response;
 *
 *--------------------------------------------------------------------*/

void readcommand (struct _file_ * port, flag_t flags)

{
	extern struct command command;
	ssize_t tmp;

#if defined (WIN32)

	PAUSE (250);
	memset (&command, 0, sizeof (command));
	tmp = read (port->file, command.buffer, sizeof (command.buffer));
	if (tmp < 0)
	{
		error (1, errno, "Bad response from %s", port->name);
	}
	if (tmp == 0)
	{
		error (1, errno, "No response from %s", port->name);
	}
	command.length = tmp;

#else

	struct timeval tv;
	fd_set rfd;
	memset (&command, 0, sizeof (command));
	while (!strchr (command.buffer, '\r'))
	{
		tv.tv_sec = 1;
		tv.tv_usec = 0;
		FD_ZERO (&rfd);
		FD_SET (port->file, &rfd);
		if (select (port->file + 1, &rfd, NULL, NULL, &tv) != 1)
		{
			error (1, errno, "Read timeout");
		}
		tmp = read (port->file, command.buffer + command.length, sizeof (command.buffer) - command.length - 1);
		if (tmp < 0)
		{
			error (1, errno, "Could not read %s", port->name);
		}
		command.length += tmp;
		command.buffer [command.length] = '\0';
	}

#endif

	if (_anyset (flags, UART_VERBOSE))
	{
		write (STDERR_FILENO, command.buffer, command.length);
		write (STDERR_FILENO, "\n", sizeof (char));
	}
	if (!memcmp (command.buffer, "ERROR", 5))
	{
		error (1, ECANCELED, "Device refused request");
	}
	return;
}


/*====================================================================*
 *
 *   void insert (char c);
 *
 *   serial.h
 *
 *   insert a character into the command buffer at the current buffer
 *   position then increment the buffer position pointer;
 *
 *--------------------------------------------------------------------*/

void insert (char c)

{
	extern struct command command;
	if (command.length < sizeof (command.buffer))
	{
		command.buffer [command.length++] = c;
	}
	return;
}


/*====================================================================*
 *
 *   unsigned readframe (signed fd, void * memory, size_t extent);
 *
 *   serial.h
 *
 *   read a file and convert hexadecimal octets to binary bytes then
 *   store them in consecutive memory locations up to a given length;
 *   return the actual number of bytes stored;
 *
 *   digits may be consecutive or separated by white space consisting
 *   of spaces, tabs, linefeeds, carriage returns, formfeeds or other
 *   characters such as punctuation; script-style comments are treated
 *   as white space;
 *
 *--------------------------------------------------------------------*/

static signed fdgetc (signed fd)

{
	char c;
	return ((read (fd, &c, sizeof (c)) == sizeof (c))? c: EOF);
}

size_t readframe (signed fd, void * memory, size_t extent)

{
	unsigned digits = 0;
	uint8_t * origin = (uint8_t *)(memory);
	uint8_t * offset = (uint8_t *)(memory);
	signed c = EOF;
	while ((extent) && ((c = fdgetc (fd)) != EOF) && (c != ';'))
	{
		if (isspace (c))
		{
			continue;
		}
		if (c == '#')
		{
			do
			{
				c = fdgetc (fd);
			}
			while ((c != '\n') && (c != EOF));
			continue;
		}
		if (c == '/')
		{
			c = fdgetc (fd);
			if (c == '/')
			{
				do
				{
					c = fdgetc (fd);
				}
				while ((c != '\n') && (c != EOF));
				continue;
			}
			if (c == '*')
			{
				while ((c != '/') && (c != EOF))
				{
					while ((c != '*') && (c != EOF))
					{
						c = fdgetc (fd);
					}
					c = fdgetc (fd);
				}
				continue;
			}
			continue;
		}
		if (isxdigit (c))
		{
			*offset = c;
			offset++;
			digits++;
			extent--;
			continue;
		}
		error (1, ENOTSUP, "Illegal hex digit '%c' (0x%02X) in source", c, c);
	}
	if (digits & 1)
	{
		error (1, ENOTSUP, "Odd number of hex digits (%d) in source", digits);
	}
	return (offset - origin);
}


/*====================================================================*
 *
 *   void decode (void const * memory, size_t extent);
 *
 *   serial.h
 *
 *   copy a memory region into command buffer at the current position
 *   and increment the buffer position pointer; convert bytes to hex
 *   octets;
 *
 *--------------------------------------------------------------------*/

void decode (void const * memory, size_t extent)

{
	extern struct command command;
	register byte * binary = (byte *)(memory);
	while ((command.length < sizeof (command.buffer)) && (extent--))
	{
		insert (DIGITS_HEX [(*binary >> 4) & 0x0F]);
		insert (DIGITS_HEX [(*binary >> 0) & 0x0F]);
		binary++;
	}
	return;
}


/*====================================================================*
 *
 *   void encode (void * memory, size_t extent);
 *
 *   serial.h
 *
 *   encode a memory region from the current command buffer position
 *   and increment the command buffer position pointer;
 *
 *--------------------------------------------------------------------*/

void encode (void * memory, size_t extent)

{
	extern struct command command;
	register byte * binary = (byte *)(memory);
	unsigned digit;
	while ((command.offset < command.length) && (extent--))
	{
		*binary = 0;
		if ((digit = todigit (command.buffer [command.offset++])) > 0x0F)
		{
			command.buffer [command.offset] = (char)(0);
			error (1, EINVAL, "[%s]1", command.buffer);
		}
		*binary |= digit << 4;
		if ((digit = todigit (command.buffer [command.offset++])) > 0x0F)
		{
			command.buffer [command.offset] = (char)(0);
			error (1, EINVAL, "[%s]2", command.buffer);
		}
		*binary |= digit;
		binary++;
	}
	return;
}


/*====================================================================*
 *
 *   void string (char * string);
 *
 *   serial.h
 *
 *   extract the contents of a quoted string string from the command
 *   buffer; it assumes that the current char is a quote character;
 *
 *   copy command buffer characters to an external string; start a the
 *   current buffer position and continue until the buffer exhausts or
 *   a closing quote is encountered; NUL terminate the string;
 *
 *--------------------------------------------------------------------*/

void string (char * string)

{
	extern struct command command;
	while ((command.offset < command.length) && (command.buffer [command.offset] != '\"'))
	{
		*string++ = command.buffer [command.offset++];
	}
	*string = (char)(0);
	return;
}


/*====================================================================*
 *
 *   uint64_t hextoint (unsigned bytes);
 *
 *   serial.h
 *
 *   this function is used to extract a hexadecimal integer string as
 *   an integer of specified length; an error occurs of the string is
 *   to long for the specified integer size in bytes;
 *
 *--------------------------------------------------------------------*/

uint64_t hextoint (unsigned bytes)

{
	extern struct command command;
	uint64_t limit = -1;
	uint64_t value = 0;
	unsigned radix = 16;
	unsigned digit = 0;
	if (bytes < sizeof (limit))
	{
		limit <<= (bytes << 3);
		limit = ~limit;
	}
	while ((digit = todigit (command.buffer [command.offset])) < radix)
	{
		value *= radix;
		value += digit;
		command.offset++;
		if (value > limit)
		{
			command.buffer [command.offset] = (char)(0);
			error (1, EINVAL, "[%s] exceeds %d bits", command.buffer, (bytes << 3));
		}
	}
	return (value);
}


/*====================================================================*
 *
 *   void mustbe (char c);
 *
 *   serial.h
 *
 *   test the character at the current buffer position; advance the
 *   buffer position pointer and return true on match; terminate the
 *   program on mismatch or exhausted buffer;
 *
 *--------------------------------------------------------------------*/

void mustbe (char c)

{
	extern struct command command;
	if (command.offset >= command.length)
	{
		command.buffer [command.offset] = (char)(0);
		error (1, EINVAL, "[%s]: overflow", command.buffer);
	}
	if (command.buffer [command.offset++] != (c))
	{
		command.buffer [command.offset] = (char)(0);
		error (1, EINVAL, "[%s]: expecting 0x%02X", command.buffer, c);
	}
	return;
}


/*====================================================================*
 *
 *--------------------------------------------------------------------*/

#endif